Differential Diagnosis for Patient with Gastric Cancer and Adjuvant Chemotherapy

The patient's symptoms and laboratory results suggest an acute condition that requires prompt attention. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Neutropenic fever with possible infection: The patient is undergoing chemotherapy, which suppresses the immune system, making them susceptible to infections. The elevated CRP and procalcitonin levels indicate a significant inflammatory response, likely due to a bacterial infection. The back and chest pain could be related to the infection or a side effect of the chemotherapy.

• Other Likely Diagnoses

  • Chemotherapy-induced neuropathy or musculoskeletal pain: The back and chest pain could be related to the chemotherapy itself, which can cause neuropathic or musculoskeletal pain.
  • Gastric cancer progression or metastasis: The patient's symptoms could be related to the progression of the gastric cancer, including metastasis to the bones or other organs.
  • Pneumonia or other respiratory infections: The chest pain and elevated inflammatory markers could indicate a respiratory infection, such as pneumonia.

• Do Not Miss Diagnoses

  • Sepsis: The patient's elevated procalcitonin level and CRP suggest a possible septic infection, which is a life-threatening condition that requires immediate attention.
  • Pulmonary embolism: The chest pain and shortness of breath (if present) could indicate a pulmonary embolism, which is a potentially life-threatening condition.
  • Spinal cord compression or epidural abscess: The back pain could be related to spinal cord compression or an epidural abscess, which are medical emergencies that require prompt intervention.

• Rare Diagnoses

  • Chemotherapy-induced cardiotoxicity: The chest pain could be related to cardiotoxicity caused by the chemotherapy, although this is a rare side effect.
  • Thrombotic microangiopathy: The patient's symptoms and laboratory results could suggest thrombotic microangiopathy, a rare condition characterized by thrombocytopenia, microangiopathic hemolytic anemia, and renal failure.
  • Inflammatory response to tumor lysis syndrome: The patient's symptoms and laboratory results could indicate an inflammatory response to tumor lysis syndrome, a rare condition that occurs when a large number of cancer cells die rapidly.